The use of safety ropes and harnesses for a person working on a perch or a platform is well known in the prior art. A more difficult challenge is to provide a fall safety device to arrest the fall of a person climbing a ladder.
Many safety and maintenance vehicles are equipped with vertically extendible devices to permit operation high above the ground. An example is an aerial ladder carried by a fire truck. These vertically extendible devices must be carefully supported and stabilized for the safety of persons using them. An aerial ladder on a fire truck, for example, is typically mounted on a rotatable base or platform which permits the ladder to be positioned at any point on a circular arc. The fire truck and ladder are stabilized by outriggers deployed outwardly on opposite sides of the truck. Such outriggers usually extend about five feet on each side of the fire truck and provide very good stabilization for any rotational position of the aerial ladder.
The platforms or aerial ladders typically are refracted in stacked sections onto a fire truck such that the length can be reduced while driving. The ladder can have three or more stacked sections that are laid on top of the others. As the ladder is set up vertically, these sections are driven upwardly extending the ladder. When full extended the ladder can reach 75 to 150 feet or more. The incline of the ladder typically is 60 degrees or more, often almost vertically oriented up to 75 degrees or so. The ladders have rungs onto which the firefighter places his or her feet to upwardly climb. The sides have handrails to help keep the firefighter from falling.
Often the firefighter is laden with heavy equipment while climbing and has much of this weight on his or her back. This magnifies the risk of losing balance and slipping. Once the start of a fall occurs, if the firefighter cannot catch oneself by grasping a rung or handrail, he or she is likely to fall. Too often this fall is fatal due to the extreme heights.
To prevent falling, the firefighter can tie himself or herself to the top of the extended ladder once he or she has climbed that far. Unfortunately, the falls often occur as the firefighter is climbing and to date there has been no way to safely secure the climbing firefighter without impeding his or her rapid ascent.
Another objective of the present device is to permit objects to be hoisted up or down a safety rope with a device that allows free movement along the safety rope, but locks up upon a weight exertion on the rope causing the device to cinch the rope.
It is therefore an object of the present invention to provide a safe and simple fall restraint device for use on such aerial ladders that secures the climbing firefighter while not interfering with the climb.
Another objective is to have the device employable with the extension of the ladder.
Another objective is to have the device not interfere with the setting up, extension or refraction of the ladder, but rather to coexist with the ladder and the climber without detrimentally getting in the way of or impeding the operation.
These and other objectives are achieved by the inventive fall restraint device described as follows.